Lee Dewyze's "American Idol" studying paid off. Crystal Bowersox showed she's an honor student in more than one subject. And Didi Benami and Tim Urban might have been wise to sleep through Tuesday night's test rather than show up and bomb so badly during their performances.

With Usher teaching the class for R&B week, there were students that continued to impress, and students that are in danger of flunking out. Let's see how they all fared with another edition of our "Idol" report card. (And don't miss Jim Cantiello's "Idol" recap of their performances in the MTV Newsroom.)

Excellent

Casey James: Simon Cowell nailed it when he said James sounded authentic during his rockin' take on Sam & Dave's "Hold on I'm Comin'. " It wasn't that the song showcased his vocal fortitude, because that's not what will win him votes. He'll continue to move forward if he comes across as a credible rock star. That's exactly what happened last night. Kudos, too, to an excellent arrangement that made use of the band's horn section and provided a satisfying counterpoint to James' bluesy vocals. But what about that maniacal grin he insisted on sporting throughout the entire performance? Rockers are supposed to be tortured souls, dude, not Paxil-assisted nutjobs.

Mike Lynche: Big Mike put his guitar to good use as he hadn't yet during the live shows (see his earlier, ungainly take on Maroon 5's "This Love"). Even during his restrained rendition of India.Arie's "Ready for Love," Lynche's confidence shined through. In an odd way, the performance was a corollary to Katelyn Epperly's "The Scientist," a soaring show piece that somewhere landed her with a premature trip home. There's no danger of that happening with Bike Mike. He's got a huge, well-deserved following.

Good

Andrew Garcia: Was a Chris Brown song a smart choice for a contestant already fighting a plummeting public image and gone from front-runner to also-ran with frightening speed? No matter! His funked-up reworking of Brown's "Forever" marked a return to relevance for Garcia. He's been lucky to squeak by in recent weeks, but his performance on Tuesday — combined with his mom's endearing tête-à-tête with Simon — should ensure Garcia another week on the "Idol" stage.

Lee Dewyze: Walking pneumonia sounds like a frightening thing, but Dewyze shook off that malady to deliver his finest performance of the season. His take on the Cornelius Brothers & Sister Rose's "Treat Her Like a Lady" was a high-energy rock romp with a little bit of country seasoning detectable here and there. For weeks it seemed he was determined to become a Kris Allen-style artist — and the danger there is how easy it is to come off as a generic singer-songwriter wannabe, the kind who plays student unions the country over but can't land a major recording contract. This time around, Dewyze stepped up his game and actually seemed like he deserved all the praise that the judges were heaping on his shoulders.

Crystal Bowersox: No one else this season communicates a fraction of the emotion that Sox does when she's up on stage. We don't think she seemed uncomfortable at the piano, at least not so much that impact of her playing was lost. While it was jarring to see Crystal dolled up in a tight dress and high heels while singing "Midnight Train to Georgia" by Gladys Knight & The Pips, she was making an argument: I'm not who you think I am. I'm so much more. No arguments from us!

Satisfactory

Siobhan Magnus: Chaka Khan's "Through the Fire" was Magnus' least-interesting song choice. The performance, along with her I'm-a-big-girl makeover, conspired to strip her of her youthful quirkiness. The song vacillated wildly in pitch and tone, culminating predictably with her patented squealing. Simon worried that Bowersox was changing to fit someone else's ideal, and we have the same concern when it comes to Magnus. She's safe this week, we think, but we want her to return to oddball form ASAP.

Katie Stevens: The 17-year-old tried on sultry and found it did not fit at all. There was absolutely no power or urgency to her rendition of Aretha Franklin's "Chain of Fools." It was perfectly fine, which is not enough at this point in the game. Dolled up with a poof, Stevens seemed as if she were playing dress-up. She landed in the bottom three last week, and we foresee a trip back there again.

Aaron Kelly: Is "meh" the most overused descriptive in online journalism? Well, to Kelly's take on "Ain't No Sunshine" by Bill Withers — one of the most overused songs in the "Idol" catalog — goes a big fat, "Meh!" As with Stevens' performance, Kelly's was perfectly fine and perfectly forgettable. And yet, it matters not at all. Kelly could croon a few pages from Obama's health care bill and he'd still have no trouble moving on to the next round.

Unsatisfactory

Didi Benami: Really, Didi? Why abandon your jazzy-pop vocal tone for that send-up of a high school musical performance? The straight-forward arrangement of "What Becomes of the Brokenhearted" presented an oddly empty sound, and Didi's chops were unable to fill the space. The segment ended in a very uncomfortable manner, with Ryan Seacrest forcefully clutching her hand and demanding she make an emotional revelation. But that's the sort of thing that could keep Didi around despite that stinker of a performance. Perhaps that was the point.

Tim Urban: Urban is the most schizophrenic of contestants, stumbling from pop-rock to reggae to R&B without making any of the songs his own. During a take on Anita Baker's "Sweet Love," his mumbling phrasings were all over the place. Afterward, though, he displayed a confidence we hadn't yet seen, a devil-may-care swagger. It's hard to fault him. "Teflon Tim" Urban can do no wrong. He's sure to end up in the bottom three again, but it's quite possible he'll survive.

How do you think the Idol hopefuls did last night? Who did the best? Who did the worst? Let us know in the comments below!

Get your "Idol" fix on MTV News' "American Idol" page, where you'll find all the latest news, interviews and opinions.